Aspects of the present invention are directed to a modular wall box system.
A conventional wall box device that controls power delivered to a load and is fed with line voltage generally integrates load actuation and user interface functionality into a single device. Such devices include, for example, light dimmers for interior spaces. These light dimmers often feature replaceable front plates that are attached through a simple snap mechanism to the dimmer device. In some cases, multiple dimmers can be ganged together and finished by application of a cover plate made for the multi-gang box. Ganging of devices makes it possible to install triac-based dimmers, FET-based dimmers, relays and timers side-by-side.
It has been shown, however, that ganging devices of multiple vendors, or even the ganging of different product series by the same vendor, can often create slight esthetic problems due to the different materials, dimensions and color variations each product line features. In order to provide for more stringent esthetics, manufactures often feature devices that differ from the typical device dimensions to avoid the problem of mismatching.
To cater to the different tastes and requirements of the public, suppliers of wall box devices also offer different user interfaces, such as dimmers combined with a toggle switch, dimmers combined with a paddle switch, dimmers combined with a push-button switch, dimmers combined with a touch screen and so on. These user interfaces need to be produced in various device types, such as a 2-way dimmer, a 3-way dimmer, a FL-light dimmer, a remote controllable dimmer and so on. Unfortunately, in current devices, should a customer desire to change the user interface, say from a toggle switch to a paddle switch, the entire device has to be dismounted. This is wasteful as a perfectly good working dimming actuator has to be removed and often discarded for the sole purpose of upgrading the user experience. Further, if this operation is performed in commercial applications, in many instances the changing of a light dimmer needs to be executed by a licensed electrician with costs associated that often exceed the cost of the dimmer itself. Another problem arises when user interfaces become significantly costlier in relation to the load actuating parts. For example, the cost of a user interface that is based on an LCD and a touch screen, or the cost of a user interface with customized artwork often exceeds the cost of the dimming actuator. Should this actuator part fail, due to an overload situation during installation, a load failure such as a burned-out light bulb or the impact of a near-by lighting strike, the entire device would have to be removed and replaced in an unnecessarily wasteful and costly procedure.
A user interface being an integral part of a load controlling device is a further burden on the manufacturer. Customers often demand that devices installed comply with local and national building codes, such as the National Electric Code (NEC) and a common request is that devices are certified by Underwriter's Laboratories (UL) and or the Electrical Testing Laboratory (ETL). When a supplier of load controlling devices introduces a new series of products, they have to go through the entire certification process, even if, in essence, the load bearing and safety related aspects stay the same and just a new housing or user interface concept is applied. This slows down the development process and increases the cost of the product development.
For the stated reasons, it is desirable to methodically decouple the load actuating device part from the user interface so that they can be treated as two separate devices from a design, systems integration, installation and maintenance view point.